A well-engineered and open source ASP.NET MVC application?

I would love to hear what HN userbase considers to be a well-engineered ASP.NET MVC application. While this term is vague, I am fairly confident that majority of you here used the term "well-engineered" or something to that end. There is a ton of blog posts/articles about various principles, patterns and best practices, but I have yet to see a single open source web application which truly covers everything. Please submit a link to the repository and discuss why you consider the application to be well-engineered.